Degradation of DC characteristics of InGaAs/InP single heterojunction bipolar transistors under electron irradiation

The effects of high-energy (similar to 1 MeV) electron irradiation on the de characteristics of InGaAs/InP single heterojunction bipolar transistors (SHBT's) are investigated. The device characteristics do not show any significant change for electron doses <10(15/)cm(2). For higher doses, devices show a decrease in collector current, a degradation of common-emitter current gain, an increase in collector saturation voltage and an increase in the collector output conductance, A simple SPICE-like device model is developed to describe the de characteristics of SHBT's. The model parameters extracted from the measured de characteristics of the devices before and after irradiation are used to get an insight into the physical mechanisms responsible for the degradation of the devices.